final db structure

db/migrate/20170403162844_create_sale_discount_items.rb

@@ -0,0 +1,19 @@
+class CreateSaleDiscountItems < ActiveRecord::Migration[5.0]
+  def change
+    create_table :sale_discount_items do |t|
+      t.references :sale, foreign_key: true
+      t.string :product_code, :null => false
+      t.string :product_name, :null => false
+      t.decimal :unit_price, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.decimal :discounted_price, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.decimal :qty, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.string :remark
+      t.decimal :price, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.string :discount_type, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.decimal :discounted_value, :precision => 10, :scale => 2, :null => false, :default => 0.00
+      t.boolean :is_taxable, :null => false, :default => true
+
+      t.timestamps
+    end
+  end
+end